Conventionally, plasma display panels (referred to below as “PDP”) are widely used in the field of display devices, and recently there have been demands for large-screen PDPs which have excellent quality but are low in cost.
PDPs are formed by laminating a front substrate and a rear substrate via a sealing material, and an electrical discharge gas is sealed thereinside. Three-electrode surface discharge technology is commonly used for PDPs in which sustaining electrodes and scanning electrodes are formed on the front substrate, and address electrodes are formed on the rear substrate. When voltage is applied between the scanning electrodes and the address electrodes so as to generate an electrical discharge, the sealed electrical discharge gas converted into plasma and ultraviolet rays are discharged. Phosphors which are formed on the rear substrate are excited by the ultraviolet rays resulting in visible light being discharged.
A process for manufacturing a PDP includes a coating step of applying the sealing material onto a peripheral edge portion of the rear substrate, and a sealing step of laminating and sealing the front substrate and the rear substrate. In the sealing material coating step, the sealing agent transformed into paste is applied onto the rear substrate. Therefore, a sealing material is employed in which is mixed a binder which is made of solvent and resin component. Moreover, after the sealing material has been applied, a drying step is performed (for example, at a temperature of 120° C. for 10 to 20 minutes) in order to remove the solvent, and a temporary baking step (for example, see Non-patent document 1) is also performed in order to remove the resin component. In the temporary baking step, a rear substrate which has completed the drying step is firstly heated in air or in an oxygen atmosphere from a temperature of 120° C. to 320° C. over a temperature increase time of 5° C. to 10° C. per minute. Next, the rear substrate is heated from a temperature of 320° C. to 380° C. at a temperature increase rate of 4° C. per minute. The rear substrate is then held at a temperature of 380° C. for 10 minutes. Thereafter, the rear substrate is cooled to room temperature at a temperature decrease rate of 5° C. to 50° C. per minute. It is noted that the heating is performed at a gentle pace is in order to ensure the dissolution and combustion of the binder.    [Non-patent document 1] “Encyclopedia of Flat Panel Displays”, Tatsuo Uchida et. al., December 2001, pp 752-754, 868-869